MUNICH, Feb. 7Edging closer toward airstrikes against Iraq, Defense Secretary William S. Cohen met with his counterparts from Europe's four biggest nations today to enlist their support, as a U.S. congressional delegation here suggested that the extent of America's future commitment to NATO would hinge on European backing of the U.S. position on Iraq.

Cohen declared there was "no definite time line or deadline set" for military action, but his aides announced that he had signed the deployment orders sending 42 additional military aircraft to the Persian Gulf region. The action made clear that while administration officials still hold out the prospect of a diplomatic solution to the confrontation with Iraq, they continue to prepare steadily for war.

In New York, meanwhile, U.S. Ambassador to the United Nations Bill Richardson, ending an 18,000-mile trip across three continents, said he found among leaders of the countries he visited a "silent majority" supportive of U.S. policy toward Iraq including, if necessary, military action to make Baghdad cooperate with U.N. weapons inspectors.

On Monday, Richardson will join British diplomats in lobbying for support within the 15-nation Security Council for a resolution that would declare Iraq in "material breach" of council resolutions ordering the elimination of Iraqi weapons of mass destruction. The Clinton administration contends that existing council resolutions authorize the use of force against Iraq, but Britain wants a new resolution that would apply specifically to the current situation.

British support was underscored today in Washington when visiting Prime Minister Tony Blair joined President Clinton in his weekly radio address to reaffirm their warnings to Iraq.

Blair, who returned home shortly after taping the address, said "no issue has been more pressing" in his discussions with Clinton and members of Congress than Iraq's defiance of U.N. inspections.

"This is a man who has already compiled sufficient chemical and biological weapons to wipe out the world's population. . . . He must be stopped," Blair said. If diplomacy fails "and force is the only way to get him into line, then force will be used."

In lobbying NATO allies, Cohen had help from several leading senators who accompanied him here to a European conference on strategic issues. With German Chancellor Helmut Kohl and prominent members of Europe's defense establishment in the audience, the senators warned that failure to support the United States in its confrontation with Iraq would undermine the Atlantic alliance.

"Make no mistake," declared Sen. John W. Warner (R-Va.), the second-ranking Republican on the Armed Services Committee, "there is a direct relationship between decisions taken on Iraq in the next weeks and months and the future U.S. support for NATO. We will be watching very carefully the support that our allies give us."

The same message was delivered by two other senior committee members, Sens. John McCain (R-Ariz.) and Joseph I. Lieberman (D-Conn.), who stressed that while they did not necessarily agree in such political linkage, many in the United States would not forgive Europe if it declined to maintain a common front against Iraq.

"Iraq's continued efforts to maintain a biological and chemical weapons arsenal threaten peace in the Middle East and ultimately threaten us all," McCain said. "We need to stick together to deny [Iraqi President] Saddam Hussein this arsenal."

In response, Kohl declared his government's "full political backing and support" for the U.S. approach and offered to make air bases in his country available to U.S. aircraft involved in any Persian Gulf operation.

Kohl's gesture appeared spontaneous but had little more than symbolic value, because Pentagon officials said they have no plans to use bases in Europe to stage any attacks on Iraq. Still, the offer was welcomed by Cohen, who departs Sunday for talks with leaders in the Persian Gulf states about U.S. war plans.

"I believe the best way to avoid any need to resort to military action in this regard is for all of our NATO friends, U.N. members, those in the Security Council in particular perhaps, to reaffirm their commitment to their own resolutions," Cohen said.

Of the major NATO powers, only Britain is preparing to take part in any military campaign against Iraq. France is the other European power with a permanent seat on the U.N. Security Council and military aircraft already positioned in the gulf region, helping U.S. and British squadrons enforce a ban in Iraqi military flights over southern Iraq. But the French, who have been attempting to mediate a diplomatic solution with Iraq, have not committed to participating in air strikes.

Cohen appeared to make little progress today during a meeting with his French counterpart, Alain Richard, in gaining a French commitment to back military action should diplomacy fail.

"They are going to continue to seek a diplomatic solution and will continue to work at that effort," Cohen said of the French position. "They will await the result of that effort before making any further determination."

Cohen's sessions with other defense ministers -- George Robertson of Britain, Volker Ruehe of Germany and Beniamino Andreatta of Italy -- drew stronger expressions of support, according to participants.

After the round of afternoon meetings, Cohen signed the order for the additional planes. The deployment, signaled earlier in the week, will double to 12 the number of F-117 stealth jet fighters in Kuwait, increase from two to three the B-1 bombers in Bahrain, raise from eight to 14 the B-52 bombers on the island of Diego Garcia and provide other aircraft for search and rescue, refueling and suppression of enemy air defense missions.

U.N. ambassador Richardson visited eight capitals in Europe, Africa and South America to consult with leaders from eight of the Security Council's 10 nonpermanent members, which serve two-year terms. They are Sweden, Portugal, Slovenia, Gambia, Kenya, Gabon, Brazil and Costa Rica. Talking with reporters in a telephone conference interview, he said:

"They all are committed to the proposition that Iraq must allow U.N. inspectors unfettered access to all suspected weapons sites. . . . There is a real fear out there that Iraq continues to develop dangerous weapons, and there is far broader support for our efforts to stop Saddam Hussein than has been reported because so much attention is focused on disagreements among the permanent council members [which include China and Russia]."

The council imposed strict sanctions on Iraq following its 1990 invasion of neighboring Kuwait, and after Iraq's defeat in the 1991 Persian Gulf War, the sanctions were kept in place until the council is satisfied that all Iraqi weapons of mass destruction have been eliminated. But, for the past three months, inspectors from the U.N. Special Commission (UNSCOM) charged with searching for possible biological and chemical warfare programs have been barred by Iraq from many suspected sites.

That has led Clinton to warn that if Baghdad does not back down, it faces substantial retaliation from U.S. warplanes and missiles. But the effort to back up the threat with a new Security Council resolution has been clouded by opposition from Russia and China, who insist the dispute must be settled diplomatically. Both are permanent council members with the power to veto any resolution, and U.S. officials fear they would use it even if a majority of the council favors a declaration that Iraq is in "material breach" of the council's orders and subject to military measures.

"We want to see all diplomatic avenues exhausted," Richardson said. "But the diplomacy right now is on life support. We frankly don't see much hope it will succeed."

Asked what the United States would consider an acceptable diplomatic result, he said: "The solution for us is clear, unfettered, unconditional access to all sites and all applicable documents. That is the red line for any diplomatic solution."

Staff writer John M. Goshko at the United Nations contributed to this report.